Use drop_begin (NFC)

Author: kazutakahirata

bolt/lib/Passes/Inliner.cpp

@@ -288,12 +288,12 @@ Inliner::inlineCall(BinaryBasicBlock &CallerBB,
   // Copy basic blocks and maintain a map from their origin.
   std::unordered_map<const BinaryBasicBlock *, BinaryBasicBlock *> InlinedBBMap;
   InlinedBBMap[&Callee.front()] = FirstInlinedBB;
-  for (auto BBI = std::next(Callee.begin()); BBI != Callee.end(); ++BBI) {
+  for (const BinaryBasicBlock &BB : llvm::drop_begin(Callee)) {
     BinaryBasicBlock *InlinedBB = CallerFunction.addBasicBlock();
-    InlinedBBMap[&*BBI] = InlinedBB;
+    InlinedBBMap[&BB] = InlinedBB;
     InlinedBB->setCFIState(FirstInlinedBB->getCFIState());
     if (Callee.hasValidProfile())
-      InlinedBB->setExecutionCount(BBI->getKnownExecutionCount());
+      InlinedBB->setExecutionCount(BB.getKnownExecutionCount());
     else
       InlinedBB->setExecutionCount(FirstInlinedBBCount);
   }

llvm/lib/Analysis/MustExecute.cpp

@@ -59,10 +59,11 @@ void SimpleLoopSafetyInfo::computeLoopSafetyInfo(const Loop *CurLoop) {
   // The first block in loopinfo.Blocks is guaranteed to be the header.
   assert(Header == *CurLoop->getBlocks().begin() &&
          "First block must be header");
-  for (Loop::block_iterator BB = std::next(CurLoop->block_begin()),
-                            BBE = CurLoop->block_end();
-       (BB != BBE) && !MayThrow; ++BB)
-    MayThrow |= !isGuaranteedToTransferExecutionToSuccessor(*BB);
+  for (const BasicBlock *BB : llvm::drop_begin(CurLoop->blocks())) {
+    MayThrow |= !isGuaranteedToTransferExecutionToSuccessor(BB);
+    if (MayThrow)
+      break;
+  }
 
   computeBlockColors(CurLoop);
 }

llvm/lib/LineEditor/LineEditor.cpp

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/LineEditor/LineEditor.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/Path.h"
@@ -37,13 +38,11 @@ std::string LineEditor::ListCompleterConcept::getCommonPrefix(
   assert(!Comps.empty());
 
   std::string CommonPrefix = Comps[0].TypedText;
-  for (std::vector<Completion>::const_iterator I = Comps.begin() + 1,
-                                               E = Comps.end();
-       I != E; ++I) {
-    size_t Len = std::min(CommonPrefix.size(), I->TypedText.size());
+  for (const Completion &C : llvm::drop_begin(Comps)) {
+    size_t Len = std::min(CommonPrefix.size(), C.TypedText.size());
     size_t CommonLen = 0;
     for (; CommonLen != Len; ++CommonLen) {
-      if (CommonPrefix[CommonLen] != I->TypedText[CommonLen])
+      if (CommonPrefix[CommonLen] != C.TypedText[CommonLen])
         break;
     }
     CommonPrefix.resize(CommonLen);

llvm/lib/MC/MCAsmStreamer.cpp

@@ -565,10 +565,8 @@ void MCAsmStreamer::emitAssemblerFlag(MCAssemblerFlag Flag) {
 void MCAsmStreamer::emitLinkerOptions(ArrayRef<std::string> Options) {
   assert(!Options.empty() && "At least one option is required!");
   OS << "\t.linker_option \"" << Options[0] << '"';
-  for (ArrayRef<std::string>::iterator it = Options.begin() + 1,
-         ie = Options.end(); it != ie; ++it) {
-    OS << ", " << '"' << *it << '"';
-  }
+  for (const std::string &Opt : llvm::drop_begin(Options))
+    OS << ", " << '"' << Opt << '"';
   EmitEOL();
 }
 

llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp

@@ -1115,11 +1115,10 @@ void AArch64AsmPrinter::LowerFAULTING_OP(const MachineInstr &FaultingMI) {
   if (DefRegister != (Register)0)
     MI.addOperand(MCOperand::createReg(DefRegister));
 
-  for (auto I = FaultingMI.operands_begin() + OperandsBeginIdx,
-            E = FaultingMI.operands_end();
-       I != E; ++I) {
+  for (const MachineOperand &MO :
+       llvm::drop_begin(FaultingMI.operands(), OperandsBeginIdx)) {
     MCOperand Dest;
-    lowerOperand(*I, Dest);
+    lowerOperand(MO, Dest);
     MI.addOperand(Dest);
   }
 

llvm/lib/Target/X86/X86MCInstLower.cpp

@@ -1313,10 +1313,9 @@ void X86AsmPrinter::LowerFAULTING_OP(const MachineInstr &FaultingMI,
   if (DefRegister != X86::NoRegister)
     MI.addOperand(MCOperand::createReg(DefRegister));
 
-  for (auto I = FaultingMI.operands_begin() + OperandsBeginIdx,
-            E = FaultingMI.operands_end();
-       I != E; ++I)
-    if (auto MaybeOperand = MCIL.LowerMachineOperand(&FaultingMI, *I))
+  for (const MachineOperand &MO :
+       llvm::drop_begin(FaultingMI.operands(), OperandsBeginIdx))
+    if (auto MaybeOperand = MCIL.LowerMachineOperand(&FaultingMI, MO))
       MI.addOperand(*MaybeOperand);
 
   OutStreamer->AddComment("on-fault: " + HandlerLabel->getName());

llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp

@@ -4461,11 +4461,9 @@ struct VarArgMIPS64Helper : public VarArgHelper {
   void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override {
     unsigned VAArgOffset = 0;
     const DataLayout &DL = F.getParent()->getDataLayout();
-    for (auto ArgIt = CB.arg_begin() + CB.getFunctionType()->getNumParams(),
-              End = CB.arg_end();
-         ArgIt != End; ++ArgIt) {
+    for (Value *A :
+         llvm::drop_begin(CB.args(), CB.getFunctionType()->getNumParams())) {
       Triple TargetTriple(F.getParent()->getTargetTriple());
-      Value *A = *ArgIt;
       Value *Base;
       uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
       if (TargetTriple.getArch() == Triple::mips64) {

llvm/lib/Transforms/Scalar/LoopDistribute.cpp

@@ -461,16 +461,14 @@ class InstPartitionContainer {
     // update PH to point to the newly added preheader.
     BasicBlock *TopPH = OrigPH;
     unsigned Index = getSize() - 1;
-    for (auto I = std::next(PartitionContainer.rbegin()),
-              E = PartitionContainer.rend();
-         I != E; ++I, --Index, TopPH = NewLoop->getLoopPreheader()) {
-      auto *Part = &*I;
-
-      NewLoop = Part->cloneLoopWithPreheader(TopPH, Pred, Index, LI, DT);
-
-      Part->getVMap()[ExitBlock] = TopPH;
-      Part->remapInstructions();
-      setNewLoopID(OrigLoopID, Part);
+    for (auto &Part : llvm::drop_begin(llvm::reverse(PartitionContainer))) {
+      NewLoop = Part.cloneLoopWithPreheader(TopPH, Pred, Index, LI, DT);
+
+      Part.getVMap()[ExitBlock] = TopPH;
+      Part.remapInstructions();
+      setNewLoopID(OrigLoopID, &Part);
+      --Index;
+      TopPH = NewLoop->getLoopPreheader();
     }
     Pred->getTerminator()->replaceUsesOfWith(OrigPH, TopPH);